Signal horn



Oct. 29, 1957 R. D. BUI-:LL

SIGNAL' HORN Filed April 20, 1954 SIGNAL HORN Roy D. Buell, Chicago,lll.

Application April 20, 1954, Serial No. 424,420

v9 Claims. (Cl. 116-142) This invention relates to a signal horn andmore particularly to an extremely compact, powerful and highly efficienthuid-actuated signal horn.

According Vto this invention a vibratory diaphragm is supported byilexible means connected to the diaphragm at its periphery so that thediaphragm can be of minimum size and maximum strength and yet bedisplaceable through a greater distance to generate more power withgreater efficiency.

According to a specific feature of the invention, the flexible meanssupporting the periphery of the vibratory diaphragm extends inwardly andis supported from a point opposite a central portion of the vibratorydiaphragm. With this arrangement, the flexible support means need notextend beyond the periphery of the diaphragm and thus a more compacthorn construction is achieved.

According to a further specific feature of the invention the flexiblesupport connected to the periphery of the vibratory diaphragm comprisesa second diaphragm supported in spaced aligned relation to the vibratorydiaphragm with the peripheries of the two diaphragms being connected andwith means connected to the central portion of the second diaphragm forsupporting the same. With this arrangement, the flexible support meansis simple and readily provided and it does ont project beyond theperiphery of the vibratory diaphragm so that the compact construction isachieved.

The support of the periphery of the vibratory diaphragm through a seconddiaphragm is particularly advantageous where the vibratory diaphragm isactuated by pressurized uid means acting against one face thereof and itis desired to seal the other face thereof from the pressurized fluid,since a sealing connection between the peripheries of the diaphragms canbe readily provided.

It is sometimes desirable that such other face of the diaphragm beconnected to some other source of fluid or iluid chamber. In accordancewith a specific feature of the invention, this may be achieved byproviding a suitable port or the like in the support means for thecentral portion of the support diaphragm.

The signal horn may preferably be of a type in which the diaphragm ismounted within a chamber and supported for vibratory movement into andout of closing relation to an exit opening from the chamber, and inwhich a source of pressurized fluid is connected to the chamber. In thistype of horn construction, the fluid acts to move the diaphragm awayfrom the exit opening to allow flow of iluid through the exit opening.This ilow reduces the pressure acting on the diaphragm so that it mayreturn to its original position in closing relation to the exit openingwhereupon pressure builds up in the chamber to again force the diaphragmaway from the opening. This cycle of operation is automatically repeatedin fast sequence so that a modulated flow of fluid is achieved throughthe exit opening and an audible sound signal is generated. A suitablehorn or the like may be connected to the exit opening from the chamberfinite States Patent() f 2,811,129 Patented Oct. 29, 1957 CCu toincrease eiciency and to direct the generated sound wave in a desireddirection.

In accordance with a further feature of the invention, the support meansfor the exible means connected to the vibratory diaphragm is adjustablymovable toward and away from the exit opening of the chamber to adjustthe operation of the signal horn. In addition, or in the alternative,the exit opening may be dened by a member adjustably mounted formovement toward and away from the diaphragm support means.

In accordance with a still further feature of the invention, thevibratory diaphragm may be normally positioned out of closing relationto the exit opening to permit a steady ow of pressurized iluid outthrough the exit opening. When it is desired to initiate operation ofthe horn, the space behind the vibratory diaphragm may be pressurized tourge the diaphragm into closing relation to the opening. Pressure maythen build up to move the diaphragm out of such closing relation to theopening, the pressure will then decrease due to the flow and thediaphragm may again close the opening. This cycle is, of course,repeated in fast sequence to generate a sound wave, which will continueas long as the space between the vibratory ldiaphragm is pressurized.

In one preferred embodiment of the invention, the vibratory and supportdiaphragms may have integral rim portions extending toward each other,such rim portions having interengaged outwardly projecting flanges withone of the anges being folded over the other to secure the diaphragms insealed relation.

ln another preferred embodiment of the invention, an annulus of rigidmaterial may be disposed between the peripheral portions of theVvibratory and support diaphragms and may be sealingly secured thereto.

With the signal horn of this invention, it has been found possible toreduce the size of the driver unit of a signal horn to less than halfthe size of the conventionally constructed driver unit, and yet obtain apower output and eiiiciency .greater than that obtained with theconventional construction.

An object of this invention, accordingly, is to provide a signal horn orthe like which is extremely compact, powerful and highly eicient.

A more specific object ofV this invention is to provide a signal hornincluding a vibratory diaphragm supported, by a flexible means connectedto the diaphragm at its periphery.

AnotherV object of this invention is to provide an improved signal hornin which a vibratory diaphragm is supported by means of a diaphragm inspaced aligned relation to the vibratory diaphragm with the twodiaphragms being connected together at their peripheries, and with thesecond diaphragm being supported centrally.

A further object of this invention is to provide an improved signal hornutilizing a vibratory diaphragm actuated by a pressurized uid to controlilow of the fluid, the diaphragm being supported by exible meansconnected to the diaphragm at its periphery.

Still anotherobject of the present invention is to provide an improvedmanner of initiating operation of a signal horn.

A still further object of this invention is to provide improved meansfor connecting the peripheries of a'pair of the diaphragms together in asignal horn or the like.

Yet another object of this invention is to provide an' with theaccompanying drawing which illustrates preferred embodiments and inwhich:

Figure 1 is a side elevational view of a signal horn constructed inaccordance with the principles of this invention;

Figure 2 is an enlarged sectional View through a portion of the signalhorn of Figure l to illustrate the internal construction;

Figure 2a is a View similar to the portion of Figure 2 illustrating amodified construction;

Figure 3 is a sectional view taken substantially along line III--H'I ofFigure 2; and

Figure 4 is a view similar to Figure 2 but illustrating anotherpreferred form of signal horn constructed according tothe principles ofthis invention.

Reference numeral generally designates a signal horn constructedVaccording to the principles of this invention which may comprise a horn11 and a fluid-actuated driver unit 12.

The driver unit 12 may have a housing defined' by a pair of generallycup-shaped members 13 and 14 having rims sealingly secured togetherthrough a threaded connection 15 and delining a'chamber 16 adapted tobe'connected to a source of pressurized fluid through an internallythreaded opening 1-7 in the housing member 12. The pressurized fluidmay, for example, be compressed air or the device may be connected tothe exhaust manifold of an internal combustion engine.

The housing member 14 may have a central` opening 18 defining anexitopening from the. chamber 16 and the housing member 14 may have an.integral external boss portion 19 about the opening 18 arranged toreceive the end of the horn 1.1. The housing member 14 may also have anintegral inwardly projecting annular lip 20 aboutthe inner end of theopening 18.

A vibratory diaphragm. 21 is supported within the chamber 16 formovement' into. and out of engagement; with the lip 20, into and out ofclosing relation to. the opening 18.

According to this invention, the vibratory diaphragm 21 is supportedwithin the chamber 16I by exible means connected to the diaphragm 21 atthe periphery thereof which means may most preferably comprise` asecond,

diaphragm 22 having its periphery connected` to, the

periphery ofthe diaphragm` 2,1 and having a central portion. supportedfrom thehousing defined by the members 13 and 14.

To connect the peripheries` of the vibratory diaphragm 21 and thesupport diaphragm 22, the diaphragms 21 and 22V may have integral 'rimportions 23 andV 24, respectively, with these rim portions 23 and 24having interengaged outwardly projecting flanges 2S and 26,respectively. One of the flanges 25, 26, for example the flange 26 maybe wider than the other and may be foldedback over the other to securethe diaphragms 21 and 22 in sealed assembly.

To support the support diaphragm 22 from the housing, a member 27 isprovided having a head portion 28 engaging the inner surface of thediaphragm 22 and a shank portion 29 extending through a central aperturein the diaphragm 22 and threaded into a central opening in the housingmember 13; The diaphragm 22 may be securely fastened to the member 27 inany desired manner, as by welding, brazing or soldering. The threadedinterengagement. between the shank portion 29 of the membery 27 and thehousing 13 permits adjustment of the position of member 27 relative tothe housing, to adjust the operation of the signal' horn 10.

pose, the outer end of the shank portion 29 of the member 27 may have anannular flange or lip 31.

In the operation of the signal horn 10, the vibratory diaphragm 21 maybe urged to va position as illustrated in closing relation to the exitopening 18. Fluid under pressure admitted through the opening 17 intothe chamber 16 will urge the diaphragm 21 out of closing relation to theexit opening 18 to allowV ilow of the pressurized lluid through theopening 18 into the throat of the horn 11. Due to the resiliency of thediaphragm 21 and the resilient -support of the periphery thereof throughthe diaphragm 22, the movement of the diaphragm 21 away from the lip 20about the opening 18 may be quite large and the diaphragm 21 may, forexample, assume a position as illustrated in dotted lines in Figure 2 toallow a large ow of the fluid into the horn 11.

Flow through the exit opening 18 into the horn 11 will, of course,reduce the pressure within the chamber 16 andthe inherent resiliency ofthe diaphragms 21 and 22, as well as increased pressure in the spacebetween the diaphragms may force the diaphragm 21 back toward closingrelation to the exit opening 18, against the reduced pressure within thechamber 16. When the diaphragm To provide communication with the spacebetween the 21 is again moved into closing relation to the opening 18,fluid pressure may again build up within the chamber 16 to force thediaphragm 21y toward its dotted-line position as illustrated in Figure 2out of closing relation to the opening 18. This cycle will be repeatedin extremely fast sequence to produce a modulated flow of pressurizedair into the horn 11, and thus generate an audible sound wave. Thefrequency of the sound wave which may, for example, be from to 1000cycles per second is determinedv by the resiliency ofthe diaphragms 21and 22, the mass of the diaphragms 21 andv 22, the pressure at thesource of pressurized iluid, the resistance of the flow path betweensuch source and the chamber 16, and various other factors. This`frequency may be adjusted by adjustingthe position of the member 27relative to the housing and, for maximum output, is adjusted intoresonance with the bell or horn 11 which, of course will resonate at acertain frequency determined by its length and flare. When the member 27has been moved to the desired position, a lock nut 32 may be turned intotight engagement with the endl of an annular boss 33 of the housingymember 13.

The operation of the horn-10 may alsobe adjusted to some extent byproviding for a limited flow of pressurized air from the chamber 16 intothe space between the diaphragms 21 and 22. For this purpose, the rimportion 22'y of the diaphragmA 21 may be provided with a smallopening.34 as'illustratedrin Figure 2A. j

It may be notedk that the operation of the signal horn lflfis alsoaffected by the size of the portl 30 in the support member'27`. In some.cases, it may be desirable to completely close the port 3i); In generalhowever, it is desirable, to. have; som'e path from the space betweenthe diaphragms 2'1 andv 22:. to the space outside the housing of theunit 12', to prevent pressure from building up in such space in thefeventv there is leakage from the space 15; to: the spacebetween theydiaphragms 21 and22.

According to a further feature of. the invention, the support member27mightv be moved to the left from the position as illustrated in Figure2; so that the diaphragm 2,1? is-'outof closing relationto theiexitopening 18. Pressurized iuidi admitted: at4 the opening 17 may then owthrough.theexitopening 1S into thefhorn'll without generating a soundWave. Whenzitt is then desired to initiate operationof the unit, apressurized fluid may beadmittedk through the port 30 intothe spacebetween the diaphragms,

21 and 22 to urge'the: diaphragm 21 into closing relation.

to the exitropening 181 'Ihetunitt 10Jwill then operate to generateasound wave andwill continue to operate as-long asthe pressure ismaintained between the diaphragms 21 andi22.

It should be notedfthatfthe diaphragms 21 and 22, and" the housingmembers 13 and 14 'are most preferably of circular form, for ease ofconstruction and assembly and for reliable operation, as is illustratedin Figure 3.

In Figure 4, reference numeral 35 illustrates a modied signal horn whichmay comprise a horn 36 and a driver unit 37. The driver unit 37 may beconstructed in a manner similar to the driver unit 12 as above describedand may comprise a pair of generally cup-shaped housing members 38 and39 having rim portions secured in sealed relation through a threadedconnection 40. The housing member 39 may have a central internallythreaded opening 41 with an annular external boss 42 therearound, theopening 41 being adapted to threadingly receive an externally threadedsleeve 43 defining an exit opening from a chamber 44 defined by thehousing members 38 and 39 the throat end of the horn 36 being disposedin such opening. This opening is designated by reference numeral 45.

The housing 39 may also have an internally vthreaded opening 46 forreceiving coupling means for establishing communication between thechamber 44 and a source of uid under pressure.

A diaphragm 47 corresponding to the diaphragm 21 in the signal hornabove described, is supported within the chamber 44 for movement intoand out of closing relation to the exit opening 45 by means of a seconddiaphragm 48 having its periphery connected to the periphery of thediaphragm 47 and having a central portion supported from the housingmember 38.

For connecting the peripheries of the diaphragms 47 and 48, an annularring 49 of rigid material may be disposed between and securely axed tothe peripheries of the diaphragms 47 and 48.

The central portion of the diaphragm 48 may be connected to the housingmember 38 through a support member 50 substantially identical to themember 27 of the signal horn 10 above described, the member 50 beinglocked in any desired adjusted position relative to the housing member38 by a lock nut 51. The member 50 also has an outer lip 52, like thelip 31 of the member 27 above described, for sealingly engaging theinternal surface of a tube 53 of exible material communicating with thespace between the diaphragms 47 and 48 through a port 54 in the member50. The tube 53 is connected to a bulb 5S of flexible material which maybe manually collapsed.

The support 50 may be so positioned relative to the support sleeve 43for the horn 36 that the diaphragm 47 is out of closing relation to theexit opening 45, to permit a uniform ow of the pressurized uid from theinlet opening 46 through the exit opening 45, without generating anysound wave. The chamber 44 may thus be permanently connected to a sourceof pressurized uid.

To initiate operation of the signal horn 35, the bulb 55 may becollapsed to increase the pressure in the space between diaphragms 47and 48 to force the diaphragm 47 into closing relation to the exitopening 45. Pressure may then build up within the chamber 44 to forcethe diaphragm 47 out of contact with the end of the sleeve 43 to permitow of uid from the chamber 44 through the exit opening 45 into thethroat of the horn 46. This flow will, of course, reduce the pressurewithin the chamber 44 thus allowing the diaphragm 47 to move back intoclosing relation to the opening 45. This cycle of operation will berepeated in fast sequence to 'achieve a modulated flow of fluid throughthe opening 45 into the signal horn 36 to generate an audible soundwave. continue as long as the pressure is maintained in the spacebetween the diaphragms 47 and 48 by collapsing of the bulb 55.

When the pressure on the bulb 55 is released, the fluid in the spacebetween the diaphragms 47 and 48 may flow through the port 54 and tube53 to the bulb 55 to restore the original pressure condition and stopoperation of the signal horn 35.

'I'his sound wave will It will be apparent that the bulb 55 maybecorinected through the tube 53 to the member 27 of the signal horn 10to control the operation thereof.

By way of illustrative example and not by Way of limitation, thediaphragms 21, 2.2 or 47, 48 may have diameters of approximately one andone-half inches and the housing defined by the members 13, 14, or thehousing defined by the members 38, 39 may have a diameter ofapproximately two inches. With such dimensions, the units 10 and 35 willdevelop as much power as a ve inch diaphragm in a six inch housing of 'aconventional construction, and with equal if not better efficiency.

This, of course, is apparently due tothe unique support of theperipheral portion of the vibratory diaphragms through the supportdiaphragms.

The diaphragms 21, 22, 47 and 48 may most preferably be of berylliumcopper, or other material having a very low fatigue factor.

It should be noted that the support diaphragms need not be directlysupported from the housings but may be supported from ilexible meanssuch as additional exible diaphragms. A bellows-like arrangement ofdiaphragms may, for example, be used. Y

It will be understood that other modiiications and variations may beeiected without departing from the spirit and scope of the novelconcepts of the present invention.

I claim vas my invention:

1. In a signal horn, a vibratory diaphragm, pres surized fluid meansacting on one side of said diaphragm to vibrate the same, and means forboth supporting said diaphragm and for sealing the other side of saiddiaphragm from said pressurized fluid means, comprising: a supportVdiaphragm in spaced aligned relation to said vibratory diaphragm, means.sealingly connectingthe peripheries of said diaphragms, and meanssupporting a central portion of said support diaphragm.

2. In a signal horn, a vibratory diaphragm, pressurized fluid meansacting on one side of said diaphragm to vibrate the same, and means forboth supporting said diaphragm and for sealing the other side of saiddiaphragm from said pressurized uid means, comprising: a supportdiaphragm in spaced aligned relation to said vibratory diaphragm, meanssealingly connecting the peripheries of said diaphragms, and meanssupporting a central portion of said support diaphragm, and having aport in communication with the space between said diaphragms.

3. In a signal horn, a housing defining a chamber adapted to beconnected to a source of pressurized uid and having an exit opening, avibratory diaphragm having one face arranged to seal said opening, asupport diaphragm disposed in spaced aligned relation to the other faceof said vibratory diaphragm, means connecting the peripheries of saiddiaphragms, and means supporting a central portion of said supportdiaphragm from said housing.

4. In a signal horn, a housing defining a chamber adapted to beconnected to a source of pressurized iluid and having an exit opening, avibratory diaphragm having one face arranged to seal said opening, asupport diaphragm disposed in spaced aligned relation to the other faceof said vibratory diaphragm, means connecting the peripheries of saiddiaphragms, and means supporting a central portion of said supportdiaphragm from said housing, and having a port in communication with thespace between said diaphragms.

5. In a signal horn, a housing dem'ng a chamber adapted to be connectedto a source of pressured fluid and having an exit opening, a vibratorydiaphragm having one face arranged to seal said opening, a supportdiaphragm disposed in spaced aligned relation to the other face of saidvibratory diaphragm, means connecting the peripheries of saiddiaphragms, and means supporting a central portion of said supportdiaphragm from said housing and adjustably movable toward and away fromsaid exit opening; v Y

6. In a signal horn, a housing delining a chamber adapted to beconnected to a source of pressurized fluid, a vibratory diaphragm insaid chamber, a support diaphragm disposed in spaced aligned relation toone face of said vibratory diaphragm, means connecting the peripheriesof said diaphragms, means supporting a central portion of said supportdiaphragm from said housing, a member deiining an exit opening from saidchamber and engageable with the other face of said vibratory di"- phragmto close said opening, and means for adjusting the positionl of saidmember relative to said housing.

7. rIn a signal horn, a housing defining a chamber adapted to beconnected to a source of pressurized iluid and having anexit opening, adiaphragm, and flexible means connected between said housing and theperiphery of said diaphragm for supporting said diaphragm within saidchamber for vibratory movement into and out of closing relation to saidopening.

8. In a signal horn, a housing deiining a chamber adapted to beconnected to a source of pressurized fiuid and having an exit opening, adiaphragm, flexible means connected? to; the periphery oi-A saiddiaphragm for supportirigl'said diaphragm Within said chamber forvibratory movement' into and out of closing relation to said opening,and means connecting said flexible means to said housing andl adjustablymovable toward and away from said opening.

9; Ina signal horn', a `housingdening a chamber adapted to be connectedtoa source of pressurized uid, a member supported by said housing anddefining an exit opening from said chamber, a diaphragm, exible meansconnected between said housing and the periphery of said diaphragmv forsupporting said diaphragm within said chamber for vibratory movementinto and out of closing relation to said opening, and means foradjusting the position of said member relative to said housing.

Reerenccsted in theiilefof this patent UNITED STATES PATENTS 1,427,281Garratt Aug. 29A, 1922 1,676,528 Critchfield July l0, 1928 2,645,198Stafford July 14, 1953

